All-terrain vehicle

ABSTRACT

Disclosed herein is an all-terrain vehicle including a body, a power generating and transmission group, and a track suspension group, each of which can be separately initially fabricated and subsequently assembled. After assembly of the power generating and transmission group and the track suspension group to the body, a motor hood, drive sprocket, and tracks may additionally be assembled to complete the vehicle. Also disclosed herein is a track suspension system affording both transverse and lateral resiliently flexible support to an endless track and a releasably locked and pivotally mounted rear bogie wheel assembly which, when pivoted from its normal operating position, affords assembly of or removal of the endless track relative to the sprocket and bogie wheels. Also disclosed herein is a track sprocket affording maximum open area for the escape of mud, snow, ice and the like. Also disclosed herein is a hydrostatic transmission including a control having a reverse lock-out preventing accidental movement of the control into position effecting reverse operation. Still further, there is disclosed herein a hydraulic oil circulating system which utilizes the gear box as a sump for the circulating system and which is in heat exchanging relation with an air circulating system.

United States Patent J espersen 14 1 Sept. 5, 1972 [54] ALL-TERRAINVEHICLE [72] Inventor: Herbert A. Jespersen, Lincoln,

Nebr.

[73] Assignee: Outboard Marine Corporation, Waukegan, Ill.

22 Filed: Aug.26, 1971 [21] Appl.No.: 175,376

Related US. Application Data [63] Continuation of Ser. No. 857,494,Sept. 12,

1969, abandoned.

[52] US. Cl. ..l80/9.62, 115/1 R, ISO/9.2 R, 180/89, 296/31 P, 305/27,305/35 EB [51] Int. Cl. ..B62d 55/00 [58] Field of Search ..115/1 R;180/5 R, 6.7, 9.2 R, l80/9.62, 54 R, 54 F, 56, 58, 64 R, 64 M, 89;296/31 P; 305/18, 27, 35 EP [56] References Cited UNITED STATES PATENTS2,397,791 4/1946 Kramer et a1. ..115/1 R 2,656,904 10/1953 Grenier..l80/6.7 X 2,734,476 2/1956 Marsh ..305/18 X 3,309,150 3/1967 Marier..305/27 3,444,837 5/1969 Donofrio ..115/1 R 3,474,751 10/1969 Hebert..115/1 R Primary Examiner-Benjamin Hersh Assistant Examiner-Leslie J.Paperner ABSTRACT Disclosed herein is an all-terrain vehicle including'a body, a power generating and transmission group, and a tracksuspension group, each of which can be separately initially fabricatedand subsequently assembled. After assembly of the power generating andtransmission group and the track suspension group to the body, a motorhood, drive sprocket, and tracks may additionally be assembled tocomplete the vehicle.

Also disclosed herein is a track suspension system affording bothtransverse and lateral resiliently flexible support to an endless trackand a releasably locked and pivotally mounted rear bogie wheel assemblywhich, when pivoted from its normal operating position, affords assemblyof or removal of the endless track relative to the sprocket and bogiewheels.

Also disclosed herein is a track sprocket affording maximum open areafor the escape of mud, snow, ice and the like.

Also disclosed herein is a hydrostatic transmission including a controlhaving a reverse lock-out preventing accidental movement of the controlinto position effecting reverse operation.

Still further, there is disclosed herein a hydraulic oil circulatingsystem which utilizes the gear box as a sump for the circulating systemand which is in heat exchanging relation with an air circulating system.

8 Claims, 18 Drawing Figures PATENTEDsEP 5 m2 3.888.858

sum 5 or g 0 NV 5 N TO 2 Hseazer 9. JESPESEA AT rozuavi ALL-TERRAINVEHICLE This is a continuation of U.S. Pat. application Ser. No.857,494, filed Sept. 9, 1969, and now abandoned.

BACKGROUND OF THE INVENTION The invention relates to so-calledall-terrain vehicles which have a high capability for travel overdifficult and rough ground contours, conditions and textures. Theinvention also relates to track vehicles and especially to vehiclesadapted to travel over snow and mud. The invention further relates tomodular construction of such vehicles.

The invention further relates to sprocket constructions and to tracksuspensions. In connection with sprocket constructions, reference ismade to U.S. Application Ser. No. 685,214 now U.S. Pat. No. 3,472,563.

The invention further relates to speed and steering controls and, inthis connection, reference is made to U. S. Pat. Nos. 644,853 and3,323,607.

The invention further relates to power generating and transmissionsystems and to air and oil circulating systems for hydraulically driventrack or other vehicles and to cooling arrangements for such systems.

SUMMARY OF THE INVENTION The invention provides a superior all-terrainvehicle capable of reliable performance over a wide range of groundconditions. One of the features of the invention resides in the modulararrangement or construction whereby major components of the vehicle canbe separately fabricated and subsequently assembled as a whole.

More specifically, the main components of the disclosed all-terrainvehicle include a body, a power generating and transmission group and atrack suspension group, each of which can be separately fabricated forfuture independent assembly with the body, thereby materially reducingthe complexity of assembling and fabricating and facilitating ease ofassembly and ready replacement in the case of need for repair or thelike.

Another of the features of the modular concept involves the use ofconventional hydraulic or hydrostatic transmission units which can bereadily connected to or removed from a gear box to provide superiortransmission operation and to afford ease of assembly and replacement.

Another of the features of the invention resides in the control systemfor the power generating and transmission group which includes a pair ofhydrostatic transmission units powered by a single internal combustionengine. The control system includes a T-bar stick controlling operationof the hydraulic transmission units to provide conditions of neutral,forward and reverse drive, as well as steering, together with a reverselock-out arrangement to prevent accidental operation in reverse.

Still another feature of the invention resides in the hydrauliccirculation system which utilizes the beforementioned gear box as thesump or reservoir for oil discharged from the hydrostatic units, therebyeconomically providing for lubrication of the various components withinthe gear box.

Still another aspect of the invention resides in the dual flow aircirculation system for cooling the oil circulation system and forsupplying combustion air to the engine, as well as for cooling of theengine.

Still another feature of the invention resides in the track suspensiongroup whereby both lateral and iongitudinal resilient support isprovided for an endless belt or track. In this regard, the tracksuspension assembly, at each side of the vehicle body, includes aplurality of paired inner and outer bogie wheels which are located ingenerally adjacent transverse relation to each other and which aresupported for vertical movement independently of each other, whereby toafford resilient transverse flexible support for the endless belts.

In addition to the foregoing, each track assembly includes a rear bogiewheel assembly which is pivotally mounted to the supporting frame so asto afford displacement of the rear bogie wheels to a positionconveniently affording placement of the endless track about the drivesprocket and around the bogie wheel assemblies. Upon such assembly, therear bogie wheel assembly is swung back into its normal operatingposition and releasably locked in place to prevent loss of the endlesstrack from the suspension assembly.

Another of the aspects of the rear bogie wheel construction is thearrangement for maintaining track tension, notwithstanding any stretchor elongation which may occur to the track.

Still another feature of the rear bogie wheel assembly is thearrangement of an elastomeric mount to afford limited resilient movementof the rear bogie wheels from their normal operating position.

Still another feature of the invention is the drive sprocketconstruction which is arranged to afford a maximum opportunity forescape of ice, snow, mud, or the like, which otherwise could have atendency to build up on the sprocket.

Still another feature of the invention resides in the generalarrangement of the various bogie wheels to the frame of the tracksuspension group and the arrangement for connection of the tracksuspension group to the body.

Still another feature of the invention resides in the relationshipbetween the bogie wheel sprocket diameter and the lugs and the inside ofthe endless track. More specifically in this regard, the lugs and thediscs are dimensioned such that, at least two teeth are always engagedwithin each bogie wheel during movement of the track, thereby reliablyassuring retention of the track in proper aligned relation to theassociated track suspension system.

In general, the principal object of the invention is to provide asuperior all-terrain vehicle which is economical to manufacture andassemble, which can be readily repaired, and which is entirely reliablein operation.

Other objects and advantages of the invention will become known byreference to the following description and accompanying drawings inwhich:

DRAWINGS I FIG. 1 is a perspective view of a track vehicle em bodyingvarious of the features of the invention.

FIG. 2 is a sectional view taken transversely of the forward portion ofthe vehicle shown in FIG. 1.

FIG. 3 is an exploded elevational view, partially broken away insection, of the power generating and transmission group, the body, andthe track suspension group of the vehicle shown in FIG. 1.

FIG. 4 is an enlarged and partially broken away view of a portion of thepower generating and transmission group and of the drive sprocketemployed in the vehicle shown in FIG. 1.

FIG. 5 is an end view of the sprocket shown in FIG. 4.

FIG. 6 is a schematic view, partially in section, of the oil circulatingsystem included in the power generating and transmission group of thevehicle shown in FIG. 1.

FIG. 7 is a front elevational view, partially in section, of a portionof the control for the power generating and transmission group of thevehicle shown in FIG. 1.

FIG. 8 is a side elevational view of the control shown in FIG. 7 withthe components being shown in their Y neutral drive condition.

FIG. 9 is a view similar to FIG. 8 with the components being shown intheir reverse drive condition.

FIG. 10 is a fragmentary view, partially in section, illustrating theconnection of the track suspension group to the body.

FIG. 1 l is a sectional view taken along line 1 1-11 of I FIG. 10.

FIG. 12 is a front elevational view, partially in section, of the frontbogie wheel assemblies incorporated in the track suspension group of thevehicle shown in FIG. 1.

FIG. 13 is a sectional view taken along line 13-13 of FIG. 12.

FIG. 14 is a sectional view taken along line 14-14 of FIG. 13.

FIG. 15 is a plan view, partially in section, of the rear bogie wheelassembly of the track suspension group.

FIG. 15 is an end elevational view, partially in section, of the rearbogie wheel assembly. shown in FIG. 15.

FIG. 17 is a sectional view taken along line 1717 of FIG. 15.

FIG. 18 is a'fragmentary perspective view of a portion of the trackemployed on the vehicle shown in FIG. 1.

GENERAL DESCRIPTION Shown in the drawings and especially in FIG. 1, isan all-terrain vehicle 11 built in accordance with the invention. Thevehicle is desirably constructed by assembling three main assemblies ormodules (See FIG. 3), namely, a body 13, a power generating andtransmission group 15, and a track suspension group 17 which includes,on each side of the vehicle, a track suspension system 21. In additionto the foregoing, full construction of the vehicle is generallycompleted by assembling a motor hood 23 over the power group and byconnecting a pair of sprockets 25 to the power group and by training anendless longitudinal and transversely flexible track 27 around thesprocket 25 and track suspension system 21 at each side of the vehicle 11.

The Body The vehicle body 13 is preferably molded of fiberglass,although other constructions and materials can be employed, to providean upwardly open hollow interior which receives the power group 15 andwhich I supports the motor hood 23 and a seat 31 (See FIG. 1),

as well as other components not specifically referred More specifically,the body includes, see FIG. 2, a center section 35 having a bottom wall37 and front and rear walls 39 and 41 respectively extending upwardlyfrom the bottom wall 37. Extending from the bottom wall 37 and from thefront and rear walls 39 and 41 are opposing side walls 43 which,together with the bottom, front and rear walls, generally complete thecenter section 35.

Located transversely on the undersurface of the bottom wall 37 (See FIG.3) are a plurality of spaced parallel downwardly open channels 45 whichare formed in the otherwise generally continuous bottom wall surface. Asexplained in greater detail hereinafter,

the channels 45 cooperate with the track suspension group 17 to permitmodular assembly while, at the same time, affording maximum verticalclearance under the bottom wall 37 and between the tracks 27, consistentwith maintaining water-tight integrity of the body and maximum depth toafford sufficient space in the center section 35 for the power group 15and for the users legs. While various arrangements are possible, thedisclosed construction includes forward, rearward, and intermediatechannels.

Extending oppositely and laterally outwardly from the upper portion ofeach of the side walls 43 are (See FIG. 2) deck or extension walls 49which, along their outer peripheries, have upwardly extending flanges 51which merge with the front and rear walls 39 and 41.

Except for a pairof opposed and aligned openings 55 (See FIG. 2), whichwill shortly be described, and except as may otherwise be indicatedherein, the resulting construction is generally continuous and thereforgenerally watertight to adjacent the top edges of the w peripherythereof to the side wall part 57 to provide,

with the adjacent side wall part, a continuous opening.

The body 13 can be provided with one or more verti cal openings, as maybe desired, to afford passage of items such as an exhaust pipe which canextend through the bottom of the vehicle and then rearwardly. Suchvertical openings can be defined by a cylinder wall having a heightabove the bottom wall 37 approximately the same as the height of the topedges of the front wall, rear wall, and flanges, whereby such verticalopenings do not detract from the watertight integrity of the body. ThePower Generating and Transmission Group The power generating andtransmission group 15 principally includes (as seen best in FIG. 3) aframe 71 which is connectable to the body 13, an engine 73, and atransmission system including a gear case or box 75. Both the engine 73and the gear box 75 are connected to the frame 71 and can, in part, beconsidered as part of the frame. Other principal components of the powergroup include a pair of hydraulic or hydrostatic transmission units 77which are connected to the gear box box 75 at the front of the powergroup 15, and a hydraulic transmission control system 81 which regu.

lates the hydrostatic transmission units to afford speed and steeringoperation. In addition, the power group includes a separate control forengine speed.

Extending from the gear box 75 is an axle means which, in the disclosedconstruction, is in the form of two generally axially aligned shafts 83.Associated with each of the axle shafts 83 to span the previouslydisclosed body openings 55 are respective L-shaped closures 85 whichhave contours conforming generally to the margins of the inner surfaceof the body 13 around the openings 55 and which include deck and sidewall portions or legs 85A and 858.

More particularly, the frame 71 can be suitably constructed in anydesired way and is arranged to be suitably connected, as by bolts or thelike, to the body. More specifically, as shown best in the upper part ofFIG. 3, the frame 71 includes a central generally horizontally extendingforwardly open U-shaped member 89 which, at its forward ends, isconnected by bolts 91 or otherwise (See FIG. 2) to plates 93 welded onextensions of the gear box 75. Adjacent its rearward end, the frame 71includes a generally vertically extending box frame member 95 which isconnected to the horizontally extending U-shaped member 89. Connected tothe upper sides of the box member are vertically extending exteriorpanels 97. The top of the box shaped member 95 supports a dashboard orinstrument panel 99. The bottom of the box shaped member 95 lies .acrossthe bottom wall 37 of the body center section 35 and is suitablyattached thereto. Extending forwardly from the bottom of the box shapedmember 95 (See FIG. 3) is a channel member 101 which supports the engine73, and which, at its forward end, is bolted to the gear box 75.

Transmission System The transmission system is powered by the engine 71and includes (See FIGS. 2 and 3) a housing 111 which constitutes boththe gear box 75 and an oil reservoir and which has opposing sides uponwhich are detachably mounted the hydraulic or hydrostatic transmissionunits 77. It is to be noted that one of the facets of the modularfeature of the invention resides in the ease of assembly and readyreplacement of the hydrostatic units 77 relative to the gear box 75.

Further in regard to the gear box construction which affords readyreceipt of the hydrostatic units, the gear box sides 113 each include(See FIG. 4) respective aligned openings 115 adapted to mate with thehydrostatic units 77 and to afford transfer of power from the gear box75 to the hydrostatic units 77. In addition, the gear box sides 113 alsoeach include respective openings 1 17 to afford passage of the outputshaft (still to be described) of the associated hydrostatic unit 77.Each such opening 117 has an outer counterbore 119 which mates with theassociated hydrostatic unit 77 and serves as a pilot to afford properalignment.

In addition, the gear box housing 111 includes means for detachablyconnecting thereto the hydrostatic units 77. While various arrangementscan be employed, in the disclosed construction, such means includes aplurality of posts or bosses 123 which extend from the respective sides113 of the gear box and receive bolts 125 which pass through a clampingmember 127V and through respective spacers 129. In turn, the clampingmembers 127 engagethe hydrostatic units 77 to insure their properassembly onthe gear box 75. Further details of the gear box constructionwill be described after description of the hydrostaticunits 77.

Each of the hydrostatic units are generally of identical conventionalconstruction and, as shown in FIG. 4, includes a housing 133 containing(See FIG. 6) a pump assembly 135 driven by (See FIG. 4) an input shaft137 having a male, splined outer end 139. Each hydrostatic unit 77 alsoincludes (See FIG. 6) a motor assembly 141 which drives an output shaft143 having its outer end machined to form a pinion 144- (See FIG. 4),and hydraulic passages 145 between the pump assembly 135 and the motorassembly 141.

The pump assembly 135 also conventionally includes a charge pump 149 anda pivotally mounted swash plate 151 which, depending upon its position,causes neutral, forward or rearward drive operation of the hydraulicallyconnected motor assembly 141. Fixedly connected to the swash plate 151is a control arm 153 which, when moved in one direction from a centeredor neutral position, provides forward drive operation of the motorassembly 141 at a speed which increases with increasing control armmovement from the neutral position and which, when moved in the otherdirection from the centered or neutral position, provides reverse driveoperation of the motor assembly 141 at a speed which increases withincreasing movement of the control arm 153 from the neutral position. I

In order to properly align the power input shaft 137 with the gear box75, the hydrostatic unit housing 133 includes a pilot sleeve portion 157which is concentricwith the power input shaft 137 and which includes aperipheral annular groove receiving an O-ring 159 which serves as aseal. When the hydrostatic unit is as sembled to the gear box, thesleeve portion 157 extends into the opening 115 and the O-ring 159provides a seal. r

In addition, the hydrostatic unit housing 133 includes (See FIG. 4)apilot boss 161 in concentric relation to the motor output shaft 143.When the hydrostatic unit 77 is assembled to the gear box 75,. the boss161 is located in the counterbore 119 and a gasket is preferablyprovided therebetween to insure against a loss of oil.

Additional detailed information on the construction of the hydrostaticunits employed-in the disclosed construction can be found in theBulletin 9507 of the Sunstrand Corporation entitled HydrostaticTransmissions Tech Manual.

Means are provided in the gear box 75 for connecting the engine outputshaft 107 to the hydrostatic unit input shafts 137. While various meanscan be employed, in accordance with the invention, the gear box 75includes, as shown in FIG. 4, an input bevel gear 165 having anelongated hub 167 serving as a stub shaft which is supported by a pairof bearings, which extends exteriorly of the gear case 75 through asuitable openpreventing axial movement of the gear 165 outwardly of thegear box 75. In addition, a suitable sealing arrangement 173 between thegear box and the stub shaft is provided.

Within the gear box, the bevel gear 165 is in mesh with another bevelgear 177 which includes a through axial bore 179 and an elongated hub181 supported for rotation by a combined radial and thrust bearing 183carried by the gear box housing 111. The gear hub 181 projectsexteriorly of the gear case 75 and within the sleeve portion 157- of theassociated hydrostatic unit and with the splined outer end 139 of thepump assembly input shaft 137 received in the axial bore 179 of the hub181. Rotational driving connection is afforded by providing the hubportion of the bore 179 with an internal female spline which readilyreceives the male spline of the hydrostatic unit upon assembly of thehydrostatic unit 77 to the gear box 75. At its other end, i.e., at thegear end of the bore, the bore is counterbored at 185 to receive one endof a cross shaft 187 which is provided at both ends with a male spline.The end of the cross shaft 187 received in the bore 179 of the gear 177,is slid into the female spline of the gear so as to rotatably couple thecross shaft 187 to the gear 177. The cross shaft 187 has an axial lengthsuch that the other end thereof is received in a collar or sleeve 189which is, at least partially, located within the pilot sleeve portion157 of the other hydrostatic unit 77. The collar 189 is provided with aninternal female spline which drivingly receives the male splines on theadjacent ends of the cross shaft 187 and the input shaft 137 of theother hydrostatic unit 77 Thus, rotation of the input gear 165 serves todrive the pump assemblies 135 of both hydrostatic units 77 throughlubricated connections in the gear box 75. g

The already mentioned axle means are at least partially included in thegear box and connect the hydrostatic unit motor assemblies 141 to therespectively associated tracks 27. In this connection, when thehydrostatic units 77 are assembled to the gear box 75, the output shafts143 extend interiorly of the gear box through the openings 117 with thepinions 144 in meshed engagement with respective gears 195 which arelocated within the gear box 75. The gears 195 are respectively fixed onthe respective axle shafts 83 which are suitably journaled in generalaxial alignment by respective radial and thrust bearings 197 carried bygear case extensions or sleeves 199 which are suitably fixed as bywelding or otherwise to the housing 1 1 1 and constitute portionsthereof. lnwardly of their outer ends, the axle sleeves 199 havesuitably fixed thereto, as by welding or otherwise, the generallyupright plates 93 which respectively include ears suitably fixed, as bythe bolts 91 or otherwise, to the forward ends of the forwardly openU-shaped frame member 89. During assembly of the power group to the body13, the before-mentioned L-shaped closure members 85 are suitably fixed,as by screws or bolts, to both the plates 93 and to the margins of thebody 13 around the body openings 55 to provide the body with watertightintegrity.

It should be noted that while the lateral distance between the outerends of the axle shafts 83 is greater than the distance between the sidewalls 43 of the body center section 35, the distance between the outerextremities of the deck parts 59 of the body openings 55 is greater thanthe lateral distance between the outer ends of the axle shafts '83.Thus, the deck parts 59 of the body openings 55 facilitate placement ofthe power generating and transmission group 15 in the body centersection 35 and, ultimately, assembly of the power group 15 to the body13. v 1

At the ends of the axle sleeves 199, suitable seals 201 are providedbetween the sleeves 199 and the axle shafts 83 to prevent entry of dirtor moisture.

After assembly of the power group 15 to the body 13, the sprockets 25(still to be described in detail) are keyed and fixed to the ends of theaxle shafts 83. If not already assembled to the body 13, the tracksuspension group 17 is also assembled to the body. Thereafter, the rearbogie assemblies, still to be described, are pivoted to permit placingof the endless track 27 around the sprockets 25 and around the bogiewheels (also still to be described) with the interior lugs of the tracksbetween the bogie wheel discs.

From the foregoing, it is apparent that, depending upon the setting ofthe respective swash plates 151, input of power from the engine 73 tothe gear box 75 can selectively result in forward, neutral or rearwarddrive conditions for each track 27.

Oil Circulation System The hydraulic components of the power generatingand transmission group 15 are hydraulically assembled together toprovide an oil circulation system which is shown diagrammatically inFIG. 6. In accordance with the invention, one of the features of the oilcirculation system is the employment of the gear case 75 as a reservoiror sump for the hydraulic oil used by the hydrostatic units 77. Anotherof the features resides in the arrangement for providing an oil flowconnection between the hydraulic motor assembly 141 of each hydrostaticunit 77 and the gear case 75. More specifically, as shown in detail inFIG. 4, oil discharged from each motor assembly 141 flows throughopenings 205 adjacent to the motor output shaft 143 and into the gearcase 75 which, as noted, serves as a sump or reservoir. Such oil in thereservoir, serves to also lubricate the gearing and bearings in the gearboxor casing 75.

Oil flows (See FIG. 6) from the gear box or case 75 through a dischargeconduit or duct 207 to the radiator or heat exchanger 79 which issupported by the frame 71 above the gear case 75 in the location shownin the top portion of FIG. 3. Oil is pumped from the radiator 79 by thecharge pump 149 of the hydrostatic units and through symmetrical branchlines or ducts 211 which communicate with respective filters 213associated with the respective pump assemblies of the hydrostatic units77. Within the hydrostatic units, oil flows from the filters 213 throughducts 215 to the charge pumps 149 and thence through passages 203 to thepump assemblies 135. From the pump assemblies 135 oil flows through theinternal passages to the motor assemblies 141 from which the oil isdumped through the openings 205 into the reservoir or sump formed by thegear case 75 for subsequent cooling and recirculatron. HydrostaticTransmission Control Speed and steering control of the vehicle areprovided by a control member or stick 225 (See upper left portion ofFIG. 3 and FIGS. 7, 8 and 9) which has a cross bar 227 at the top andwhich is mounted for fore and aft rocking movement about a horizontalpivot and pivotally support the forwardly and vertically extending.

legs 231 of a U-shaped bracket 233 having a web 235. Projectingrearwardly and horizontally from the web are spaced upper and lower yokemembers 237 and 239 having respectively aligned apertures. Extendingthrough the aligned apertures in the yoke members 237 and 239 forrotational movement relative to the yoke members and to the frame 71 isthe control stick 225.

Various means can be employed to prevent axial movement of the controlstick 225 relative to the U- shaped bracket 233. In the disclosedconstruction, such means includes an upper L-shaped member 241 havingone leg welded or otherwise fixed to the control stick above the upperyoke member 237 and having the other leg extending downwardly in spacedgenerally parallel relation to the control member 225 rearwardly of thefree end of the upper yoke member 237. Connected to the free leg of theupper L-shaped member is one leg of a lower L-shaped member 243 having asecond leg 245 extending perpendicularly to the control stick just belowthe bottom yoke member 239 and having an opening receiving the lower endof the control stick 225. Fixation of the upper L-shaped member 241 tothe control stick 225 and location of the legs immediately above andbelow the yoke members 237 and 239 affords pivotal movement of thecontrol stick 225 while preventing axial movement. Above the U-shapedbracket 233, the control stick 225 is provided with a plate 251 which isinclined to the axis of the control member 225 and which has pivotalconnections with a pair of links 253 which are respectively pivotallyconnected to the control arms 153 of the hydraulic transmission units77. The links can be constructed as shown in US. Pat. Application Ser.No. 82l,2l4. When the control stick 225 is in its neutral position, thepivotal connections between the links 253 and the plate 251 are locatedat the same lateral distance from the axis of the control stick 225 andat the same distance from, but on opposite sides of, a fore and aftplane extending through the axis of the control stick 225.

The upper end of the control stick 225 extends through an elongated slot255 in the dashboard 99 and, as previously mentioned, has fixed, at thevery top, the cross bar 227.

In operation, forward movement of the control stick 225 will displacethe links 253 forwardly so as to swing forwardly the control arms 153 ofboth hydrostatic transmission units 77, thereby actuating the swashplates 151 so as to provide pumping operation to effect forward drive ofthe motor assemblies 141. As previously noted, the speed at which thehydraulic motor assemblies 141 operate can be increased by increasingthe displacement of the control arms 153 by pushing the stick 225further forward. Pulling the stick 225 rearwardly toward the operatorfrom a position advanced forward from the neutral position will decreasethe forward speed output of the hydrostatic transmission units 77 untilthe neutral position of the control arms 153 is again achieved. Furtherrearward movement of the control stick 225 will cause the swash plates151 to operate the hydraulic motor assemblies 141 in the reversedirection with increasing speed as the control stick 225 is displacedfurther rearwardly from its neutral position. Twisting of the controlstick 225 about its own axis will cause differential movement of thecontrol arms 153 such as to swing one control arm in one direction andswing the other controlarm in the opposite direction, thereby operatingthe motor assemblies 141 at differing speeds and, possibly in differentdirections, so as to cause turning movement of the vehicle. If thecontrol stick 225 is in neutral position when the control stick istwisted on its own axis, one motor assembly 141 will run in forward andthe other in reverse, thereby permitting the vehicle to turn uponitself. If the control stick 225 is advanced from its neutral position,twisting of the control stick will cause one motor assembly 141 to runfaster in whatever direction it was going and will cause the other motorassembly 141 to run slower in the initial direction and, perhaps, toevenreverse direction.

Reverse Lock-Out The T-bar control stick 225 of the disclosed vehiclehas considerable sensitivity and it can be undesirable to permit theoperator to displace the control stick, without some sort of notice orinterruption, from forward through neutral and into reverse. Moreparticularly, when the operator senses that he is going too fast andwishes to slow up, it is undesirable to permit the operator to pull backon the control stick 225 to such extent as to shift into reverse drive.Accordingly, a releasable reverse drive lock-out system is provided.

In accordance with the invention, the reverse lockout arrangementincludes a downwardly extending lip 259 at the lower end of the L-shapedbracket 243 and a pivotally mounted stop member 261 having a blockingportion 263 which is normally in a blocking position in the path of lipmovement upon control stick movement from neutral in the direction whicheffects reverse drive. More particularly, the brackets 229 which supportthe control stick 225 also pivotally supports the stop member 261 at265. Fixedly connected to and forming a part of the stop member 261 isan L-shaped arm 267 which is pivotally connected at its outer end to arod 269 which extends upwardly through a slot in the dashboard 99 andhas a knob 271 at its upper end. The stop member 261 is releasably urgedto the blocking position by a spring 273 which is connected to the stopmember 261 and to the lower surface of the dashboard 99.

In operation, when it is desired to operate in reverse, the operatordepresses the knob 271 so as to swing the block portion 263 downwardlyabout its pivotal support at 265 and out of the possible path ofmovement of the lip 259. When the block portion 263 is so depressed, thecontrol stick 225 can then be moved to displace the lip 259 through thespace previously occupied by the block portion 263 and to bring about areverse drive condition. Continued operation in reverse drive ispermitted without holding the knob 271 in depressed position because thelip 259 prevents the block portion 263 from returning to blockingposition. However, when the control stick 225 is shifted back toneutral, the spring 273 automatically causes return of the block portion263 into position preventing reverse drive operation. The Motor HoodAfter assembly of the power generating and transmission group to thebody 13, the power group is covered by the hood or cover 23 whichincludes a front hood section 279 located forwardly of the dashboard 99and extending to almost the front of the body. As willbe referred tohereinafter, the forward hood section 279 includes side walls 281 and atop wall 283, and severalvents which form part of the air coolingsystem.

The hood 23 also includes a rear section 285 located rearwardly andunderneath the dashboard. As will be described in greater detail, therear hood section 285 also serves as a component of the air coolingsystem.

Any suitable means can be employed to releasably fasten the motor hoodsections to the power group frame and vehicle body.

Radiator and Engine Cooling System The disclosed vehicle includes a dualflow arrangement for separately inducting air for cooling of thehydraulic system and for cooling of the engine 73. More specifically,the forward motor hood section 279 has, on each side 281, a forwardscreened opening or air inlet 287 through which outside air is sucked orpumped interiorly of the hood 23. Supported by the frame 71 are bafflemeans which are provided to prevent the incoming air from flowingrearwardly or downwardly from the air inlets 287 and to convey the airsolely to the top surface of the radiator 79.

More specifically, as seen in FIGS. 2, 3 and 4, such baffle meansincludes a vertical baffle 29lwhich is supported by the frame 71 andextends generally from the bottom wall 37 of the body 13 to the fronthood section 279 and which divides the center body section 35 into aforward compartment containing the gear case 75 and into a rear or aftercompartment containing the engine 73. Such baffle means also includes(See FIG. 2) a horizontal baffle 293 which is supported by the frame 71and/or the body 13 and which extends, forwardly from the vertical baffle291 to the front of the body 13 and from the deck walls 49 to theradiator 79, thereby dividing the area in front of the vertical baffle291, i.e., the forward compartment, into a lower gear case compartmentand an upper inlet air compartment which conducts air from the forwardair inlets 287 to the radiator 79 and which is located between thehorizontal baffle 293 and the front hood section 279 and forwardly ofthe vertical baffle 291.

After passing through and cooling the radiator 79, the incoming air thenpasses downwardly into the gear case compartment and over the gear case75. The air is then drawn (See FIG. 4) through an opening 295 in thevertical baffle 291 by a fan 297 which is concentrically arranged withthe opening and which is carried on a coupling 299 connected to theengine output shaft 107 and connected through the opening 295 to thegear case coupling 171.

Air for engine cooling is drawn inwardly of the front hood sectionthrough two rearwardly located upper screened inlets 303. Such incomingair is directed rearwardly under the dashboard 99 by a baffle 305 (Seeupper portion of FIG. 3) which is supported by the frame 71 and extendstransversely and generally horizontally rearwardly from the lower edgeof the inlets 303. From under the dashboard 99, the air flows downwardlyand then reversely and into the engine compartment. Rearward diffusionof .the air is prevented by the rear hood section 285 which extends fromthe dashboard 99 to the bottom wall 37 of the center body section 35 andbetween the sidewalls 43 of the center body section. Such downward airflows past the carburetor air inlet 307 to supply combustion air to theengine 73 and is sucked toward the engine by an engine fly-wheel fan309. Air discharged by the engine fly-wheel fan 309 travels forwardlyover the engine cylinders into the forward part of the enginecompartment rearwardly of the vertical baffle 291. Such incoming enginecooling air is mixed with the air delivered rearwardly from the gearcase compartment through the opening 295 by the fan 297. Such intermixedair then exits from the engine compartment through rearward side vents311 in the side walls 281 of the front hood section 279.

The Drive Sprocket Attached to the outer ends of each of the axle shafts83 extending from the power group 15 is one of the drive sprockets 25which are constructed in accordance with the invention. The sprockets 25are arranged to provide a maximum open area for discharge of snow, mud,or the like, which otherwise might collect on the inner surfaces of thedrive sprocket while, at the same time, maximizing engagement of thesprocket with the track to afford effective and reliable pullingoperation.

The drive sprocket shown in FIGS. 4 and 5 is constructed by welding orotherwise unitizing two sprocket sections 315 which are generally ofidentical construction. Each sprocket section 315 includes a hub 317having a central keyed opening 319 affording attachment to theassociated axle 83. Extending from the hub in angularly spaced relationand in radially outwardly and obliquely inclined relation to the axis ofintended rotation are a plurality of spokes 321. While more than threespokes can be used, the illustrated construction including threeequiangularly spaced spokes 321 is preferred, as a maximum of open arearesults.

Connected to the outer ends of the spokes 321 is an annular portion ormember 323 which extends normal to the axis of the sprocket 25 and hasan inner or side surface spaced axially from the adjacent end of the hub317. In addition, the annular member 323 has an inner periphery spacedradially outwardly from the outer periphery of the hub. As aconsequence, the sprocket 25 is open both axially and radially betweenthe hub and the annular member to afford easy escape of debris whichmight otherwise tend to accumulate within and about the sprocket.

Extending axially from the annular member 323 is a It is to beespecially noted that even when the sprocket sections 315 are assembled,as by welding together, the angularity and spacing of the spokes 321,together with the location of the annular members 323 offers a maximumof escape area for mud and snow. Specifically, mud and snow can exitfrom within the sprocket in the radially outward direction and in bothaxial directions. Track Suspension Group The track suspension group 17can be assembled independently of the body 13 and the power generatingand transmission group and subsequently assembled. to the body 13independently of assembly of the power generating and transmission group15 to the body 13. In accordance with the invention, the tracksuspension group 17 includes a frame or support 341 having a pluralityof structural cross members which are respectively and individuallylocated in the respective downwardly open channels 45 formed in thebottom of the body. While various arrangements are possible, in thedisclosed construction (See the lower portionof FIG. 3), the frame 341includes a forward cross member 343 and an intermediate cross member 345and a rearward cross member 347.

The cross members 343, 345 and 347 are integrated into the frame 341 bylongitudinal beams. While various arrangements can be employed, in thedisclosed construction, two beams 349 are employed, which beams arerespectively and suitably connected to the opposite ends of the crossmembers 343, 345 and 347. If desired, the beams could be connected tothe cross members inwardly of the ends thereof.

The track suspension group 17 is connected to the body 13 to maintainthe body watertight and so as to locate the cross members 343, 345 and347 in the downwardly open channels 45 by means (See FIGS. 10, 11 and12) in the form of plates 351 which are welded or otherwise fixed tothe. cross members and which are adapted to span the ends of thechannels 45 and contact the exterior surface of the side margins aroundthe channel ends. Suitable means, such as screws or bolts 353,applicable from the exterior, can be employed to attach the plates 351to the side walls 43 of the body 13. In the specifically disclosed andpreferred construction, two spaced plates are employed on each crossmember and each plate 351 forms one leg of an L- shaped bracket havingan inwardly'extending leg 355 in engagement with and supporting theunder-surface of the bottom wall 37 of the body 13 on each side of theapplicable channel 45. The area of the plates 351 and the surfacecontact between the plates 351 and the body 13 is such that, even ifthrough bolts are used to connect the plates to the body, a watertightconnection can be reliably obtained and maintained. If desired, theinwardly extending legs 355 can also be bolted or otherwise fastened tothe body 13.

Carried along each side of the track assembly frame 341 and under theadjacent deck wall 49 is. a track suspension system. Each of thesuspension systems includes inner and outer front bogie wheels 357 and359 (See FIG. 12), intermediate inner and outer bogie wheel assemblies363 (Seebottom portion of FIG. 3), a rear bogie wheel assembly 367 andinner and outer rearward idler bogie wheels 371 and 373 (See FIG. 15).As each suspension system is identical, only one will be described.

Located at'the front end of the tracksuspensionframe 341 are the innerand outer first or'front rotatable bogie wheels 357 and 359 which areseparately supported in transversely adjacent and generally axiallyparticularly, the inner and outer bogie wheels 357 and.

359 are generally of the same construction .and, as

shown best in FIG. 14, comprise apairof transversely spaced discs 381having a laterally outwardly extending thin peripheral lip 383. Thediscs 381 are keyed or otherwise fixed to a shaft having a centralbearing 387 received in a sleeve 389 which includes, at. each end, acounterbore receiving a seal member 393 which prevents entry of dirt ormoisture into thebearing 387. In addition, each of the discs 381 isprovided with a counterbored inwardly extending hub portion 395 whichreceives the end portions of the sleeve 389 to further assist inexcluding dirt or moisture- While various arrangements can be employed,in the disclosed construction, in order to permit lessening of shockupon contact of the track 27 with large obstacles and to ease passage ofthe vehicle over large obstacles, means are provided to. support thefront bogie wheels while, at the same time, affording resilient rearwardswinging movement, thereby decreasing the anglev of the upwardly andforwardly extending track to the ground. I

As the arrangement for supporting each of the inner and outer frontbogie wheels 357 and 359 is essentially the same, only the arrangementfor supporting the outer front bogie wheel 359 will be'described.

More particularly in the disclosed construction, as shown in FIGS. 12,13 and 14, the outer front bogie wheel 359 is mounted for resilientswinging movement about the axis of the front cross member 343'by meansincluding a generally vertically extending support bar 399 and a rubbertorsion bushing assembly 401. Still more particularly, the torsionbushing assembly includes an inner sleeve 403 which is telescoped ontothe front cross member 343 into proper position and are suitably spacedand fixed thereto. The outer periphery of the sleeve is cylindrical andhas bonded thereto a ring or annulus 405 of rubber or other rubber-likeelastomeric material. Bonded to the outer cylindrical surface of thering 405 is a cylindrical metallic jacket 407 having a pair ofdiametrically radially outwardly extending ears 409. The bushingassembly is received in an upwardly'open cradle 411 which is welded or"otherwise suitably connected to the upperend' of the support bar 399 andwhichhas a pair of diametrically extending tabs 413 which mate with theears 409 and are suitably connected thereto, as by bolts or the like. Atits lower end, the support bar 399 is welded to the bogie wheel sleeve389.

The extent of the resilient pivotal movement'permitted to the frontbogie wheels 357 and 359 is deter-= mined by the torsional resistance ofthe rubber ring Intermediate its ends, the track suspension. systemfurther includesintermediate inner. and .outer bogie wheelassemblies 363each having rotatably mounted.

the inner second and third bogie wheels are generally respectivelylaterally aligned with respect to the axes of the outer second and thirdbogie wheels.

As in the case. of thefront bogie wheels, the intermediate inner a ndouter bogie wheel assemblies 363 are separately supported. Each of theintermediate inner and outer bogie wheel assemblies 363 includes meansfor supportingthe bogie wheels for resilient up and down movement andfor pivotal movement about a transverse axis located intermediate thesecond and third bogie wheels. The construction of the intermediateinner and outer assemblies is generally the same. i y

To achieve the foregoing support, the sleeves of the outer bogie wheels.are suitably connected, as by clamps 423, to the ends of a leaf spring425 which, intermediate the ends thereof, is suitably fixed, as by aclamp 427, to the web 429 of an inverted U-shaped bracket 431 havingupwardly extending legs supporting a fixed pivot 433. In turn, the fixedpivot 433 is received in a bushing or sleeve 435 which is locatedbetween the bracket legs and fixed to the lower end of a post 437depending fixedly from the intermediate cross member 345. I

While separate pivots have been provided for each of the intermediateinner and outer bogie wheels assemblies 363, a single pivot member couldbe employed to support both inner 'and outer bogie wheelassemblies andstill provide the same functional result. Thus, the intermediate bogiewheel assemblies 363 have independent pivotal movement about an axisextending transversely between the second and third bogie wheels and, inaddition, each of thebogie wheels is supported so as to afford resilientup and down movement relative to the other bogie wheel of each assembly,as well as rotative movement about its own axis.

Supported on the rear cross member 347 is the rear bogie wheel assembly367 which includes fourth and fifth inner rotatable bogie wheels 445 andfourth and fifth outer rotatable bogie wheels 445 which are respectivelylocated in transversely adjacent and axially aligned relation to thefourth and fifth inner bogie wheels.-Each of the inner and outer fourthand fifth bogie wheels 445 is of like construction to the front bogiewheels. The fourth and fifth outer bogie wheels are integrated into anouter bogie wheel sub-assembly 447 by a strut or rockerbar 449 which iswelded or otherwise fixed at its ends to the sleeves of the fourth andfifth outer bogie wheels. A similar rocker bar 451 is fixed so as tointegrate the fourth and fifth inner bogie wheels into an innersub-assembly 453.

In order to provide for independent movement of the inner and outerbogie wheel sub-assemblies 447 and 453 so as to provide bothlongitudinal and transverse flexibility, the inner and outer bogie wheelsub-assemblies each include mounting means-affording pivotal movementabout aligned axes intermediate the fourth and fifth bogie wheels.

While various arrangements can be employed to separately afford pivotalmovement for the inner and outer bogie wheel sub-assemblies 447 and 453,the arrangement for both bogie wheel sub-assemblies is the same. Onlythe arrangement at the outer bogie wheel assembly, as shown in FIG. 15,will be described in detail.

of the associated bar 449 and which receives a pivot pin 7 459. In turn,the pivot pin 459 is fixed by welding or otherwise to the spaceddownwardly extending legs 461 of a U-shaped bracket or connecting member463 which straddles the sleeve 457 and which has a connecting web 465located above the bar 449.

Also forming a part of the connecting bracket 463 is a right angleflange 467 which is welded or otherwise suitably fixed to the web 465and which serves as a point of assembly to a cross bar or member 469having welded, or otherwise suitably fixed to each end, a connectingplate or flange 471 which are respectively fixed, as by bolts 473, tothe connecting brackets 463 tain proper tension in the track. Variousarrangements,

including screw means can be employed. In the specifically disclosedconstruction, one or more shims 483 are 7 located in telescopic relationon the rear end portion 477 of the arm 479 between the telescoping tube475 and the upwardly inclined arm portion 481. As shown in FIG. 15, acotter pin 485 can be employed adjacent to the rearward end of the rearend portion 477 to prevent disconnection of the telescoping tube 475 andthe rearward end portion 477 of the arm 479.

In order to permit the endless tracks 27 to be slipped over theassociated bogie wheels and sprockets, each rear bogie wheel assembly367 is fixed to the rear cross member 347 so as to afford pivotalmovement therebetween. While various means can be utilized to providesuch pivotal construction, in the disclosed construction, the upper endof each arm 479 has fixed thereto, See FIG. 16, a bushing 491 whichreceives a pivot pin 493 extending between a pair of spaced paral lelplates or brackets 495 suitably fixed, as by welding or otherwise, tothe rear cross member 347 in adjacent outward relation to the opposedsides of the associated arm 479.

Means are provided to locate the arm 479 in proper angular relation tothe rear cross member 347 and to releasably retain the arm 479 in suchangular relation to the rear cross member 347. While variousarrangements can be employed, in the disclosed construction, such meansincludes, at the rearward end of the plates 495, upper and lower bolts497 and 499 which extend between the parallel plates above and below thearm 479 so as to confine the arm in proper angular relationship to thecross member 347. However, in order to swing the arm 479 downwardly,i.e., counterclockwise, as shown in FIG. 16, about the pivotalengagement on the pin 493, and to thereby facilitate slipping of theassociated track over-the sprocket and bogie wheels, the lower bolt 499is removable.

. Means are provided to establish a normal position for each of the rearbogie wheel sub-assemblies 447 and 453, to independently permitresilient pivotal movement of each subassembly relative to said normalposition and to limit pivotal movement of each sub-assembly from thenormal operating position. As the arrangement provided for each of theinner and outer bogie wheel assemblies 447 and 453 is generallyidentical, only the construction associated with the outer bogie wheelsubassembly 447 will be described.

While various arrangements can be employed to establish a normaloperating position and to afford resilient pivotal movement relative tosaid normal position, in the disclosed construction, an elastomeric orrubber mount or spring 503 is connected between the connecting flange471 of the bogie wheel assembly cross bar 469 and the outer sub-assemblyfore and aft bar 449. More particularly, the resilient mount 503comprises a cylindrical body of rubber or other like material havingimbeded therein separate threaded studs which extend from the oppositeends of the cylindrical body. One of said studs extends through and isbolted at 505 to a forward extension 5070f the connecting flange 471 atthe adjacent end of the rear bogie wheel cross bar 469. The other studextends through and is bolted at 509 to an upright bracket 511 which iswelded or otherwise fixed to the outer fore and aft beam 449 of theouter sub-assembly 447.

Accordingly, each sub-assembly 447 and 453 tends to assume a normalposition in which the rubber mount 503 is not under stress. However, therubber mount 503 will deform in shear to offer resilient pivotalmovement away from the normal position and to accommodate track flexurein conformance with ground conditions.

While other means can be employed, pivotal movement from the normalposition in the counterclockwise direction, as shown in FIG. 16, isessentially prevented by engagement of the rear under-surface of the web465 with the bogie sub-assembly fore and aft beam 449. Pivotal bogiesub-assembly movement in the clockwise direction from the neutralposition is limited by engagement of the sub-assembly fore and aft beam449 with (See FIG. a bent ear or tab 515 at the forward extremity of theconnector flange extension 507 to which the rubber mount 503 isconnected. Thus, each of the rear bogie wheel assemblies 367 includesinner and outer bogie wheel sub-assemblies 447 and 453 which provideflexible support to the track in both the longitudinal and transversedirections.

Also forming a part of each track suspension system are a pair of upperrearward inner and outer idler bogie wheels 371 and 373 which areconstructed in generally the same manner as the front bogie wheels. Eachof the.

rearward idler bogie wheels are respectively fixed (as shown best inFIGS. 15 and 16) by separate arms 521 which, at one end, are welded orotherwise suitably secured to the rear cross member 347 and, at theother end, are suitably fixed to the associated bogie wheels as byemployment of respective clamps 523 encircling the respective bogiewheel sleeves.

It should be noted that, generally speaking, all of the inner bogiewheels are generally longitudinally aligned and that all of the outerbogie wheels are similarly longitudinally aligned.

The Tracks The tracks 27 are of endless construction of rubberoutersurface of the tracks 27 is provided along both longitudinal edges witha rib or margin 533 which is raised to an extent less than the height ofthe treads 531 and. the studs 532. On its inner surface, each track 27includes a pair of longitudinally extending parallel series of lugs 535which are engaged by the sprocket.

teeth 325 and extend within the spaced discs 381 of the bogie wheels.

It is especially noted that the studs 532 assist the margins 533 inpreventing lateral slippage of the tracks in snow or mud or the like. Inaddition, the studs 532 are transversely located so as to be inlongitudinal alignment with the outer edges or rims 383 of the bogiewheels. Thus, the studs 532 are located in laterally outwardly adjacentrelation to the lugs 535 but on the opposite side of the track. Locationof the studs 532 in 'alignmentwith the rims 383 of the bogie wheel discs381 provides a smoother, quieter ride as thestuds 532 prevent anytendency toward track flexure which might otherwise occur as aconsequence of travel of the bogie wheels relative to flat ground.

In general, the tracks 27 are generally unbroken to obtain the greatestpossible load supporting surface andare flexible in both thelongitudinal and transverse direction. Such flexibility is illustratedin FIG. 12.

wherein the right side of the track is shown passing over an object 537which does not extend for the full width of the track.

In addition, it is noted that the diameter of the bogie wheel discs 381is so related to the size or dimensions. of the lugs 535 such that, atleast portion of two lugs are:

bottom wall having a plurality of downwardly open channels extendingtransversely of the direction of intended travel, front and rear wallsextending from said. bottom wall, opposed side wallsextending from saidbottom wall and from said front and rear walls, op-

positely projecting deck walls respectively extending laterallyoutwardly from the upper portions of said side walls, and transverselyopposed and aligned openings including respective parts extendingvertically in said side walls from above the bottom portion thereof tothe adjacent deck wall and respective parts extending in said deck wallsfrom inwardly of the outer portion thereof to the adjacent side wall, apower assembly comprising a frame connected to the interior surface ofsaid body, transversely extending axle means supported by said frame andhaving a lateral extent greater thanthe lateral distance between saidside wall parts of said openings and less than the lateral distancebetween the outer edge of said deck wall parts of said openings and apair of transversely spaced allochiral closures extending from said axlemeans and having respective contours conforming to the margins of saidbody around said opposed openings, said closures each having a side wallportion respectively secured to the margins of said side walls aroundsaid openings, and a deck wall portion extending from said side wallportion and respectively secured to the margins of said deck wallsaround said openings, a drive sprocket mounted on said axle means ateach end thereof, a track suspension assembly including a tracksuspension frame having a plurality of transverse members respectivelyreceived in said channels, and respective tracks trained around each ofsaid sprockets and supported by said track suspension frame and locatedon the opposite sides of said body.

2. A vehicle in accordance with claim 1 wherein said power assemblyalsoincludes a gear box supported by said frame and having axleextensions, an engine supported by said frame and operably connected tosaid gearbox, and wherein said axle means comprises axle shaftsrotatably mounted on said axle extensions and connectedto said enginethrough said gear box, and further including a watertight seal affordingrotation of said axles relative to said axle extensions.

3. A vehicle in accordance with claim 1 wherein said body also includesupturned flanges extending respectively from the outer portions of saiddeck walls and integrally extending from said front and rear walls.

4. A vehicle including a body comprising a continuously extending onepiece body member including a bottom wall, front and rear wallsextending from aid bottom wall, opposed side walls extending from saidbottom wall and from said front and rear walls, oppositely projectingdeck walls respectively extending laterally outwardly from the upperportions of said side walls, and transversely opposed and alignedopenings including respective parts extending vertically in saidsidewalls from above the bottom portion thereof to the adjacent deckwall and respective parts extendingin said deck walls from inwardly ofthe outer portion thereof to the adjacent side wall, a power assemblycomprising a frame connected to the interior surface of said body,transversely extending axle means supported by said frame and having alateral extent greater than the lateral distance between said side wallparts of said openings and less than the lateral distance between theouter edge of said deck wall parts of said openings and a pair oftransversely spaced allochiral closures extending from said axle meansand having respective contours conforming to the margins of the innersurface of said body around said opposed openings, said closures eachhaving a side wall portion respectively secured in watertight relationto the interior surface of the margins of said side walls around saidopenings, and a deck wall portion extending from said side wall portionand respectively secured in watertight relation to the interior surfaceof the margins of said deck walls around said openings, a drive sprocketmounted on said axle means at each end thereof, and respective trackstrained around each of said sprockets and located on the opposite sidesof said body.

5. A vehicle including a body comprising a body member having a bottomwall, side walls extending upwardly from said bottom wall, transverselyaligned and upwardly open openings in said side walls, a plurality ofdownwardly open channels extending in said bottom wall transversely, ofthe direction of intended travel, a track assembly located exteriorly ofsaid body member and including a rigid frame connected to said bodymember and including a plurality of transverse members respectivelyreceived in said channels, a separate track suspension system connectedto said frame on each side of said body, and separate tracks supportedby each of said track suspension systems, and apower assembly includingpower transmitting connections located interiorly of said body memberand power transmitting elements extending from said power transmittingconnections'and through said upwardly open openings and drivinglyconnected to said tracks.

6. A vehicle including a body comprising a body member including abottom wall, front and rear walls extending from said bottom wall,opposed side walls extending from said bottom wall and from said frontand rear walls, transversely opposed and alignedupwardly open openingsin said side walls, and a plurality of downwardly open channelsextending in said bottom wall transversely of the direction of intendedtravel, a power assembly comprising a frame connected to and locatedinteriorly of said body, a pair of oppositely projecting transverselyextending axle housings supported by said power assembly frame andextending through said openings, a pair of transversely spaced closuresextending between said axle housings and the margins of said body memberaround said opposed openings,

separate axles extending in said axle housing and including partsprojecting outwardly therefrom, a track suspension assembly locatedexteriorly of said body and including a track suspension frame connectedto said body member and including a plurality of transverse membersrespectively received in said channels, a separate track suspensionsystem connected to said track suspension frame on each side of saidbody, a separate sprocket on each of said axle parts, and separateflexible tracks trained around said sprockets and said track suspensionsystems.

7. A vehicle including a body comprising a body member including abottom wall, front and rear walls extending from said bottom wall,opposed side walls ex- I tending from said bottom wall and fromsaidfront and rear walls, and transversely opposed and aligned upwardly openopenings in said side walls, a power assembly comprising a frame locatedinteriorly of said body and connected thereto, a pair of transverse axlehousing extending independently of said body member from said frame andthrough said openings, a pair of transversely spaced closuresrespectively extending between said axle housings and the margins ofsaid side walls around said openings, and a pair of axles rotatably rearwalls, oppositely projecting deck walls respectively extending laterallyoutwardly from the upper portions of said side walls, and transverselyopposed and aligned upwardly open openings including respective partsextending vertically in said side walls from above the bottom portionthereof to the adjacent deck wall and respective parts communicatingwith said side wall parts and extending in said deck walls from inwardlyof the outer portion thereof to said side wall parts, a power assemblycomprising a frame located interiorly of said body and connectedthereto, and transversely extending axle housing extending from saidpower assembly frame and having a lateral extent greater than thelateral distance between said side wall parts of said

1. A vehicle including a body comprising a continuously extending onepiece body member including a bottom wall having a plurality ofdownwardly open channels extending transversely of the direction ofintended travel, front and rear walls extending from said bottom wall,opposed side walls extending from said bottom wall and from said frontand rear walls, oppositely projecting deck walls respectively extendinglaterally outwardly from the upper portions of said side walls, andtransversely opposed and aligned openings including respective partsextending vertically in said side walls from above the bottom portionthereof to the adjacent deck wall and respective parts extending in saiddeck walls from inwardly of the outer portion thereof to the adjacentside wall, a power assembly comprising a frame connected to the interiorsurface of said body, transversely extending axle means supported bysaid frame and having a lateral extent greater than the lateral distancebetween said side wall parts of said openings and less than the lateraldistance between the outer edge of said deck wall parts of said openingsand a pair of transversely spaced allochiral closures extending fromsaid axle means and having respective contours conforming to the marginsof said body around said opposed openings, said closures each having aside wall portion respectively secured to the margins of said side wallsaround said openings, and a deck wall portion extending from said sidewall portion and respectively secured to the margins of said deck wallsaround said openings, a drive sprocket mounted on said axle means ateach end thereof, a track suspension assembly including a tracksuspension frame having a plurality of transverse members respectivelyreceived in said channels, and respective tracks trained around each ofsaid sprockets and supported by said track suspension frame and locatedon the opposite sides of said body.
 2. A vehicle in accordance withclaim 1 wherein said power assembly also includes a gear box supportedby said frame and having axle extensions, an engine supported by saidframe and operably connected to said gear box, and wherein said axlemeans comprises axle shafts rotatably mounted on said axle extensionsand connected to said engine through said gear box, and furtherincluding a watertight seal affording rotation of said axles relative tosaid axle extensions.
 3. A vehicle in accordance with claim 1 whereinsaid body also includes upturned flanges extending respectively from theouter portions of said deck walls and integrally extending from saidfront and rear walls.
 4. A vehicle including a body comprising acontinuously extending one piece body member including a bottom wall,front and rear walls extending from aid bottom wall, opposed side wallsextending from said bottom wall and from said front and rear walls,oppositely projecting deck walls respectively extending laterallyoutwardly from the upper portions of said side walls, and transverselyopposed and aligned openings including respective parts extendingvertically in said side walls from above the bottom portion thereof tothe adjacent deck wall and respective parts extending in said deck wallsfrom inwardly of the outer portion thereof to the adjacent side wall, apower assembly comprising a frame connected to the interior surface ofsaid body, transversely extending axle means supported by said frame andhaving a lateral extent greater than the lateral distance between saidside wall parts of said openings and less than the lateral distancebetween the outer edge of said deck wall parts of said openings and apair of transversely spaced allochiral closures extending from said axlemeans and having respective contours conforming to thE margins of theinner surface of said body around said opposed openings, said closureseach having a side wall portion respectively secured in watertightrelation to the interior surface of the margins of said side wallsaround said openings, and a deck wall portion extending from said sidewall portion and respectively secured in watertight relation to theinterior surface of the margins of said deck walls around said openings,a drive sprocket mounted on said axle means at each end thereof, andrespective tracks trained around each of said sprockets and located onthe opposite sides of said body.
 5. A vehicle including a bodycomprising a body member having a bottom wall, side walls extendingupwardly from said bottom wall, transversely aligned and upwardly openopenings in said side walls, a plurality of downwardly open channelsextending in said bottom wall transversely of the direction of intendedtravel, a track assembly located exteriorly of said body member andincluding a rigid frame connected to said body member and including aplurality of transverse members respectively received in said channels,a separate track suspension system connected to said frame on each sideof said body, and separate tracks supported by each of said tracksuspension systems, and a power assembly including power transmittingconnections located interiorly of said body member and powertransmitting elements extending from said power transmitting connectionsand through said upwardly open openings and drivingly connected to saidtracks.
 6. A vehicle including a body comprising a body member includinga bottom wall, front and rear walls extending from said bottom wall,opposed side walls extending from said bottom wall and from said frontand rear walls, transversely opposed and aligned upwardly open openingsin said side walls, and a plurality of downwardly open channelsextending in said bottom wall transversely of the direction of intendedtravel, a power assembly comprising a frame connected to and locatedinteriorly of said body, a pair of oppositely projecting transverselyextending axle housings supported by said power assembly frame andextending through said openings, a pair of transversely spaced closuresextending between said axle housings and the margins of said body memberaround said opposed openings, separate axles extending in said axlehousing and including parts projecting outwardly therefrom, a tracksuspension assembly located exteriorly of said body and including atrack suspension frame connected to said body member and including aplurality of transverse members respectively received in said channels,a separate track suspension system connected to said track suspensionframe on each side of said body, a separate sprocket on each of saidaxle parts, and separate flexible tracks trained around said sprocketsand said track suspension systems.
 7. A vehicle including a bodycomprising a body member including a bottom wall, front and rear wallsextending from said bottom wall, opposed side walls extending from saidbottom wall and from said front and rear walls, and transversely opposedand aligned upwardly open openings in said side walls, a power assemblycomprising a frame located interiorly of said body and connectedthereto, a pair of transverse axle housing extending independently ofsaid body member from said frame and through said openings, a pair oftransversely spaced closures respectively extending between said axlehousings and the margins of said side walls around said openings, and apair of axles rotatably carried in said axle housings and includingrespective parts extending exteriorly of each of said housings,respective drive sprockets mounted on each of said axle parts, andrespective tracks trained around each of said sprockets and located onthe opposite sides of said body.
 8. A vehicle including a bodycomprising a body member including a bottom wall, front and rear wallsextending from said bottom wall, opposed side walls extendIng from saidbottom wall and from said front and rear walls, oppositely projectingdeck walls respectively extending laterally outwardly from the upperportions of said side walls, and transversely opposed and alignedupwardly open openings including respective parts extending verticallyin said side walls from above the bottom portion thereof to the adjacentdeck wall and respective parts communicating with said side wall partsand extending in said deck walls from inwardly of the outer portionthereof to said side wall parts, a power assembly comprising a framelocated interiorly of said body and connected thereto, and transverselyextending axle housing extending from said power assembly frame andhaving a lateral extent greater than the lateral distance between saidside wall parts of said openings and less than the lateral distancebetween the outer edge of said deck wall parts of said openings, a pairof transversely spaced allochiral closures extending between said axlehousing and the margins of said body around said opposed openings,separate axles extending respectively in said axle housings andincluding respective parts projecting outwardly therefrom, respectivedrive sprockets mounted on said projecting parts of said axles, andrespective tracks trained around each of said sprockets and located onthe opposite sides of said body.